The South-East Asia Region of the World Health Organization (WHO), home to a quarter of the global population, faces several public–health challenges and high disease burdens with relatively weak health systems. The social, cultural and economic situations in the Region are quite distinct and demand innovative solutions suited to local communities. Lessons learned need to be rapidly disseminated within the Region to stimulate adaptation and application. In 2009, the WHO South-East Asia Advisory Committee on Health Research endorsed the recommendation of the regional meeting on research priorities in communicable diseases that the WHO South-East Asia Regional Office should facilitate sharing and dissemination of research by various means, including a public-health journal. These factors prompted the Regional Office to begin quarterly publication of the WHO South-East Asia Journal of Public Health in 2012.

The World Health Assembly in its first meeting in 1948 decided to celebrate 7 April of each year, with effect from 1950, as World Health Day. The day marks the founding of the World Health Organization; each year a theme is selected that highlights a priority area of publichealth. The theme for 2014 is vector-borne diseases – illnesses to which more than half of the world's population are at risk.

In recent years, vector-borne diseases have emerged as serious public-health problems worldwide, particularly in the South-East Asia Region. These diseases still represent a significant threat to human health despite considerable national and international efforts. Population growth, urbanization, migration and poor environmental sanitation are some of the major causes of the emergence and re-emergence of vector–borne diseases. Control of vectors remains a major component in disease management but the effectiveness of the available vector-control methods is limited by logistic problems, high cost, insecticide resistance and concerns about environmental pollution. Vector-borne diseases have not only adversely affected human health but also impeded overall socioeconomic development. While we have gained considerable insights into the transmission biology and management of certainvector-borne diseases over the past few decades, limited capacity exists to apply that knowledge.

To mark World Health Day 2014, this special issue of the WHO South-East Asia Journal of Public Health is devoted to vector-borne diseases. The 18 articles cover a range of current research and policy aspects of vector-borne diseases, including malaria, dengue, Kyasanur forest disease and Crimean-Congo haemorrhagic fever. The articles are from different countries in the Region including the Democratic Republic of Korea, Maldives and Timor-Leste. We conclude this special issue by reproducing the classic article by Sir Ronald Ross published in the British Medical Journal in 1897. Ross, whose research was done in the South-East Asia Region, would go on to receive the Nobel Prize in Physiology or Medicine in 1902 “for his work on malaria, by which he has shown how it enters the organism and thereby has laid the foundation for successful research on this disease and methods of combating it.”

I sincerely hope that readers will find this special issue very informative and useful.